Calorimetric investigation of copper binding in the N-terminal region of the prion protein at low copper loading: evidence for an entropically favorable first binding event.

ABSTRACT: Although the Cu(2+)-binding sites of the prion protein have been well studied when the protein is fully saturated by Cu(2+), the Cu(2+)-loading mechanism is just beginning to come into view. Because the Cu(2+)-binding modes at low and intermediate Cu(2+) occupancy necessarily represent the highest-affinity binding modes, these are very likely populated under physiological conditions, and it is thus essential to characterize them in order to understand better the biological function of copper-prion interactions. Besides binding-affinity data, almost no other thermodynamic parameters (e.g., ΔH and ΔS) have been measured, thus leaving undetermined the enthalpic and entropic factors that govern the free energy of Cu(2+) binding to the prion protein. In this study, isothermal titration calorime

SUBMITTER: Gogineni DP 

PROVIDER: S-EPMC4303328 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature